MX2009000116A - Penem prodrugs. - Google Patents

Abstract

Orally bioavailable prodrugs of sulopenem, e.g., Formula (I) and solvates and hydrates thereof, preparation thereof, formulation thereof, and use to treat and prevent infection in mammals such as humans.

Description

PENEM PROFARMACOS FIELD AND BACKGROUND OF THE INVENTION The present invention relates to antiinfectives, antibiotics, oral antibiotics and prodrugs, in particular to sulopenem prodrugs, their preparation and use. US 5013729 describes sulopenem, which is a broad spectrum antibiotic which can be referred to as (5R, 6S) -6 - [(1 R) -1-hydroxyethyl] -7-oxo-3 - [[(1 R, 3S)] ) -tetrahydro-1-oxide-3-thienyl] thio] -4-azabicyclo [3.2.0] hept-2-en-2-carboxylic acid. See also J. Org. Chem., 57, 4352-61 (1992). Other penems and prodrugs are described, for example, in US 4952577; US 5506225; WO 1992/003444; and WO 2004/067532. Several preclinical and clinical studies have been carried out with sulopenem and certain prodrugs thereof. Sulopenem itself does not have an appreciable oral bioavailability. US 5013729 also discloses sulopenem prodrugs, which include the prodrug of sulopenem pivaloyloxymethyl (POM ester of sulopenem). When administered orally in the form of a mixture of two stereoisomers, it was shown that the POM ester exhibited oral bioavailability in humans. See Foulds and cois. Antimicrobial Agents and Chemotherapy, pages 665-671 (April 1991). Without However, POM ester prodrugs are associated with the decrease of carnitine in tissues after the hydrolysis and release of pivalic acid or trimethylacetic acid. See Brass, Pharmacological Reviews, 54, 589-598 (2002).

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to the desire for new prodrugs of sulopenem that combine one or more of: exposure or elevated oral bioavailability, lack of propensity to decrease carnitine in tissues, physicochemical properties such as crystallinity, melting point, solubility in water and permeability, which are favorably suitable for practical pharmaceutical formulation and use. In some aspects, the present invention includes the compounds of Formula I: In other aspects, the present invention includes the compounds of formula II: The invention further includes the formulations and the use of the compounds to treat or prevent a bacterial infection.

DETAILED DESCRIPTION OF THE INVENTION Compounds The present invention includes the prodrug compounds of Formulas I and II, as shown and described above. All its stereoisomers and their mixtures are contemplated and included, as indicated in the previous drawings that allow and encompass both the R and S configurations of the stereocenters. A preferred configuration of the compounds of Formulas I In particular, the oxothiolanyl moiety preferably has a R 3 S configuration, as shown below.

For example, it is provided: (5R, 6S) -6 - [(1 R) -1-hydroxyethyl] -7oxo-3 - [((1 R, 3S) -tetrahydro-1-oxido-3-t-ene carboxylate (2-ethyl-1-oxobutoxy) methyl (Compound 1 herein), which is depicted below: Another example provides: (5R, 6S) -6 - [(1 R) -1-hydroxyethyl] -7-oxo-3 - [[(1 R, 3S) -tetrahydro-1-oxido-3-thienyl ^ carboxylate (2-ethoxy-2-methyl-1-oxopropoxy) methyl (Compound 2 herein), which is depicted below: The prodrugs of the present invention may be amorphous or may exist in different crystalline or polymorph forms, including solvates and hydrates. The polymorphs of the prodrugs are part of this invention and can be prepared by crystallization of a prodrug of the present invention under various conditions. Polymorphs can be obtained also heating or melting a prodrug followed by gradual or rapid cooling. The presence of polymorphs can be determined by NMR spectroscopy with solid probe, IR spectroscopy, differential scanning calorimetry, fine crystal diffraction by X-ray or other similar techniques. Thus, naming a compound per se is open to its polymorphs that include water molecules or solvents associated with them.

Preparation The prodrugs of the present invention can be prepared, for example, from the free acid of sulopenem according to known procedures such as those described herein or in US 3951954; US 4234579; US 4287181; US 4452796; US 4342693; US 4348264; US 4416891; US 4457924; and US 5013729, all of which are incorporated by reference herein in their entirety.

Use The prodrugs of this invention can be used to treat a variety of nosocomial and out-of-hospital infections such as respiratory, surgical, central nervous system, gastrointestinal, genitourinary, gynecological, skin and soft tissue and eye infections, and extrahospital pneumonia in humans. The antibacterial activity of the prodrugs can also be exploited advantageously for preventive use. Oral administration is preferred. The biological activity data are provided below. The minimum amount of prodrug that is administered is a minimum therapeutically effective amount. The maximum amount of prodrug that is administered is that amount that is toxicologically acceptable. In some embodiments, the amount of sulopenem prodrug that is administered is that which will maintain the antibiotic concentration in sulopenem plasma above the CIMg0 (minimum inhibitory concentration at 90%) (e.g., about 0.5 pg / ml or about 1 pg / ml) of the infectious pathogens for at least about 30% (for example, at least about 3.6 hours for administration twice a day or 2.4 hours for a three times daily administration) of the interval between doses. In some embodiments, the blood level is maintained at or above the target level for at least about 40% (for example, at least about 4.8 hours for administration twice a day or 3.2 hours for administration three times a day). day) of the interval between doses. In general, a daily dose of the adult sulopenem prodrug may be about 500 mgA (milligram equivalents of sulopenem) to about 6 gA, or about 1 gA to about 5 gA. A dosage regimen of the sulopenem prodrug for adults can be from about 500 mgA to about 1500 mgA administered twice daily with intervals of approximately 12 i hours A dosage may be administered for a period of about one week to about two weeks. For certain infections, it may be necessary or desirable to use doses outside these parameters. A daily dose of the prodrug of the present invention can usually be administered 1 to 4 times a day, usually in equal doses. In some embodiments, the dose of the prodrug may be from about 500 to about 2500 mg twice a day or three times a day; about 800 mg to about 1 g twice a day; or approximately 2 g twice a day or three times a day for more serious infections. In some embodiments, the dose may be from about 7 to about 25 mg / kg twice a day; from about 17 to about 45 mg / kg twice daily; or from about 17 to about 45 mg / kg three times a day. In some embodiments, treatment is initiated intravenously with sulopenem itself or with another antibiotic and then treatment with an oral prodrug of the present invention is continued. As described below, it was found that in humans the prodrug of Compound 1 provided blood levels greater than 0.5 pg / ml for between 3.18 and 4.84 hours after oral administration of 1000 mg (approximately 730 mg equivalents of sulopenem) of the prodrug . In a different experiment, it was found that in humans the prodrug of Compound 1 provided blood levels higher than f 1 g / rnl for between 4.28 and 5.94 hours after oral administration of 2000 mg (approximately 1460 mg equivalents of sulopenem) of the prodrug. The use of the prodrug may be concomitant with other active agents. The use of sulopenem or prodrug of sulopenem may be concomitant with probenecid or an agent of similar activity that has an inhibitory effect on the secretion of the renal tubules.

Formulation The present invention includes pharmaceutical compositions comprising the compound (s) of the prodrug of the invention formulated for oral administration with or without one or more excipients and / or one or more other active ingredients. The prodrug may be in the form of a solvate or hydrate. The forms for oral administration of the present invention may be tablets, which include chewable tablets, capsules, pills, tablets, troches, powders, syrups, elixirs, solutions and suspensions, and the like, in accordance with standard pharmaceutical practice.

The pharmaceutical composition of the present invention can also be administered directly to the gastrointestinal tract of the patient through a nasogastric tube. An oral dosage form in some embodiments may contain from about 800 to about 2500 mg of the prodrug. The excipients can be chosen based on the form Pharmaceutical purported Non-limiting examples include polyvinylpyrrolidone, hydroxypropylmethylcellulose, hydroxypropylcellulose, sucrose, gelatin, gum arabic, gum tragacanth or corn starch; fillers such as microcrystalline cellulose, lactose, sodium citrate, calcium carbonate, dibasic calcium phosphate, glycine and starch; disintegrants such as corn starch, potato starch, alginic acid, sodium starch glycolate, croscarmellose sodium and certain complex silicates; lubricants such as magnesium stearate, sodium lauryl sulfate and talc; and sweeteners such as sucrose, lactose or saccharin. When a single dose dosage form is a capsule it may contain, in addition to the materials of the above type, a liquid carrier such as a fatty oil. The excipients may also include suspension adjuvants such as xanthan gum or hydroxypropylmethylcellulose, glidants such as colloidal silica, diluents and bulking agents such as silicon dioxide, flavors, in particular in the case of pediatric oral suspensions and sachets. Stabilizers such as succinic acid can also be used. Various other materials may be present as coatings or to modify the physical form of the pharmaceutical form. For example, the tablets may be coated with lacquer, sugar or both. Pharmaceutical forms of modified release are also contemplated. The prodrug (s) will be present in the pharmaceutical composition in an amount sufficient to provide the amount of therapeutic dose desired in the range described herein. The proportional relationship between a prodrug and the excipients f will naturally depend on factors such as the chemical nature, solubility and stability of the active ingredients, as well as the pharmaceutical form contemplated. Usually, the pharmaceutical compositions of the present invention may contain from about 20% to about 95% prodrug by weight.

Biological activity of sulopenem Sulopenem is active against a wide range of pathogens, including hospital pathogens. This includes potent activity against members of the Enterobacteriaceae family that express expanded spectrum β-lactamases that confer resistance to cephalosporins (pneumoniae, ESBL +). In addition, many of these isolates are also resistant to fluoroquinolones. Sulopenem is very active against many clinically relevant anaerobic species. The in vitro activity of sulopenem (acid progenitor acid (5R, 6S) -6 - [(1 R) -1-hydroxyethyl] -7-oxo-3 - [[(1 R, 3S 4-thia-1-azabicyclo [3.2.0] hept-2-en- 2-carboxylic acid) was evaluated against pathogens involved in extrahospital and intrahospitalary infections, as summarized in Table 1.

TABLE 1 CIMao values (g / ml) for Sulopenem 1 Staphylococcus aureus s. to oxacillin 0.125 Staphylococcus saprophyticus 0.5 Alloiococcus otitidis 1 Streptococcus pyogenes (Group A) 0.03 Streptococcus agalactiae (Group B) 0.125 Streptococcus bovis (Group D) 0.06 Group of Streptococcus viridans 0.25 Streptococcus pneumoniae susceptible to penicillin 0.03 Streptococcus pneumoniae intermediate to penicillin 0.25 Streptococcus pneumoniae resistant to penicillin 1 Streptococcus pneumoniae resistant to levofloxacin 0.5 Listeria monocytogenes 0.125 Corynebacterium spp (not C. jium) 2 Citrobacter diversus 0.06 Citrobacter freundii 0.25 Enterobacter aerogenes 0.5 Enterobacter cloacae 1 Escherichia coli 0.06 Klebsiella oxytoca 0.125 Klebsiella pneumoniae 0.125 Klebsiella pneumoniae ESBL + 0.25 Morganella morganii 2 Proteus mirabilis 0.5 Salmonella / Shigella 0.125 Haemophilus influenzae ß-lactamase - 0.25 Haemophilus influenzae ß-lactamase + 0.5 Moraxella catarrhalis ß-lactamase - 0.03 Moraxella catarrhalis ß-lactamase + 0.125 Legionella pneumophila 0.06 Neisseria meningitides 0.06 Bacteroides fragilis 0.5 Clostridium períringens 0.06 Prevotella spp. 0.125 Thus, sulopenem is active against a wide range of pathogens, including hospital pathogens that are resistant to cephalosporins and fluoroquinolones. The spectrum supports its wide hospital use, when the infectious pathogen is identified and susceptibility to sulopenem is confirmed. This would include a broad list of respiratory indications and surgical indications in which a mixed flora would probably be involved, particularly as part of a regimen with multiple drugs when mixed infections are suspected.

Oral efficacy of the prodrugs The compounds were analyzed for oral efficacy in three different infection models in vivo. The bacterial pathogens that were used to establish each infection were chosen based on their profiles of resistance and ability to cause infection in models relevant to diseases in humans. The strains isolated from Klebsiella pneumoniae 1 109 and 6485 come from a collection of isolated clinical strains recently positive for extended-spectrum β-lactamases (ESBL +) and have high CIs of ciprofloxacin and ceftazidime as well as other ß-lactam antibiotics. Both isolated strains have demonstrated the ability to cause lethal systemic infections in mice. Streptococcus pneumoniae 1095 is a strain tolerant to penicillins, resistant to macrolides that is pathogenic in murine models of systemic infection and respiratory tract. The strain of Haemophilus influenzae r Rd / AH5-3 was derived from laboratory strain Rd; a point-directed mutation in PBP3 makes this negative strain for β-lactamase resistant to ampicillin (BLNAR). This strain is capable of causing otitis media in a model of the disease in Mongolian gerbils. The results are summarized in Table 2 below.

Murine model of acute systemic infection For this model, CF-1 mice were infected by intraperitoneal injection of a lethal inoculum of K pneumoniae 1 109, 6485, or S. pneumoniae 1095. Four groups of doses formed by eight to ten were infected. mice per group and were treated covering a wide range of dose levels. The mice were given treatment twice a day or at 30 minutes / 4 hours after infection or one / five hours after infection; DP5o (the dose at which 50% of the infected and treated mice survive) was calculated based on the numbers of animals that survived on day four after infection.

Murine model of respiratory tract infection This model of infection was initiated with an intranasal inoculation of a lethal exposure of S. pneumoniae 1095 that caused pneumonia. Four dose groups consisting of eight to ten mice per group were infected and treated to cover a wide range of dose levels. A treatment was started twice a day 18 hours after infection and continued for two days. The number of mice that survived in each dose group on the tenth day after infection was used to determine the DP50.

Model in otitis media gerbils To establish otitis media, Mongol gerbils were infected by intrabullar inoculation with a BLNAR strain of H. influenzae. Four dose groups consisting of five gerbils per group were infected and treated, covering a broad spectrum of dose levels. Treatment was started three times a day 18 hours after infection and continued for two days. On day four after infection, the animals were sacrificed, fluid washes from the middle ear were collected and the number of bacteria they contained was determined. ED50s were calculated based on bacterial levels; fluid wash samples from the middle ear with counts less than 100 colony-forming units / ml were considered clean. Data was collected for the compounds of Compounds 1 and 2; for Compound A (shown below); and for Compound B1, which is the pivaloyloxymethyl ester (POM ester) of sulopenem (stereochemistry of oxothiolane (1R, 3S)) (shown below). Compound B2 is the diastereomeric mixture (shown below). r Compound A: Compound B1: Compound B2: r TABLE 2 Efficacy in vivo (DPso or ED50 in mg / kg) Clinical Pharmacokinetics of Prodrugs The clinical pharmacokinetics (PK) data of healthy human volunteers for the compounds of the sulopenem prodrug of Compound 1, Compound B2 (data from Foulds et al.), And Compound A are summarized in Table 3, later. Compound B2 is a diastereomeric mixture of which the configuration diastereomer (1R, 3S) in the oxothiolanyl moiety is Compound B1 (see the above drawings). No clinical data are available for the prodrug of Compound 2. For Compound 1 and Compound A, six people received increasing doses. Whole blood samples were obtained before administering the dose and at 0.5, 1, 2, 3, 4, 6, 8, and 12 hours after the dose and processed to obtain the plasma. The concentration of sulopenem in the serum and plasma samples was then quantified using validated HPLC procedures. The Tmax data for Compound A are expressed in terms of median and range. A single dose of Compound B2 was administered to a total of ten people. See Foulds et al., Previous reference. Blood samples were obtained before the dose and at 0.08, 0.17, 0.33, 0.5, 1, 1.5, 2, 3, 4, 6 and 8 hours and were processed to obtain serum after oral administration of Compound B2 at 500 mg parent compound equivalents sulopenem (five people) and 1000 mg parent compound equivalent sulopenem (five people). Foulds et al. Also estimate the contributions to the PK of the 1 R, 3S diastereomers (Compound B1) and 1 S.3R present in Compound B2.

TABLE 3 Clinical pharmacokinetics of Compound 1, Compound B2 and Compound A Exposure to sulopenem after oral administration of Compound B2 was expressed in terms of the absorbed fraction compared to the intravenous AUC in the same study (Table 4, Foulds et al.) The fraction absorbed varied from 38.5 to 33.5% for Compound B2 at equivalent doses of sulopenem from 205 to 409 mg. Using the same intravenous data from Table 4 of Foulds et al., An absorbed fraction of 37.1 and 28.0% for Compound 1 can be estimated at equivalent doses of sulopenem of 292 and 438 mg, respectively. Although different dose equivalents were administered, the trend for prodrugs is for increases in systemic exposure proportionally lower than the dose. The data for Compound A demonstrate at least that the increased lipophilic ability of the prodrug does not necessarily translate into better oral exposure. The lipophilic capacity (ClogP) was calculated using the ACD Labs 9.0 program (LogP / DB; www.acdlabs.com) with the following results: Compound 1: -0.29; Compound A: 0.83; Compound B1: -1.0; Compound B2: -1.0. Further evaluation of Compound A revealed its inherent instability in the gastrointestinal tract. Improved gastrointestinal stability such as that demonstrated by Compound 1 in vitro using human intestinal juices has been correlated with an increase in dose-related oral exposure.

Evaluation and selection of prodrugs Prodrugs were evaluated with the ultimate goal of identifying compounds that showed or were predicted to exhibit one or more of the following: favorable pharmacokinetics such as exposure or elevated oral bioavailability in humans after oral administration; lack of propensity to decrease carnitine in tissues; and physicochemical properties favorably adapted to practical pharmaceutical formulation and use. The evaluation of Compound A, among other things, led to the conclusion that the gastrointestinal stability of the prodrug is predicted to play a significant role in oral bioavailability. New prodrug compounds were evaluated and classified, as explains in detail below, based on its stability in the presence of porcine pancrelipase (PPE) and its stability in human intestinal juices (HIJ). The conversion efficiency in sulopenem in human liver homogenate was also considered to be a significant parameter relative to the oral bioavailability of the prodrugs. The in vitro endpoints for Liver S9, PPE and HIJ are summarized in Table 4. Prodrugs were analyzed according to the following general procedures.

Hepatic conversion efficiency S9 The prodrugs were evaluated to determine the stability and conversion efficiency in homogenate of human liver (fraction S9). The S9 liver was freshly prepared from pieces of liver stored at -70 ° C for each analysis that was completed. Approximately 5 g of frozen liver tissue were homogenized to uniformity in 15 ml of ice-cold 100 mM potassium phosphate buffer (at pH 7.4). The homogenate was then centrifuged at 9000 g for 20 minutes at 5 ° C to isolate the S9 supernatant fraction. Each incubation was performed at a 1: 10 dilution of the S9 supernatant in 100 mM potassium phosphate buffer (at pH 7.4). The reactions (1 ml) were initiated by the addition of the substrate (50 μ final) at 37 ° C. Aliquots (75 μ?) Were obtained at 0, 0.5, 1, 2, 3, 5, 10, and 20 minutes and inactivated in 150 μ? of acetonitrile / 100 mM ammonium acetate 80/20 at pH 4.5 containing an internal standard (ampicillin, 5 pg / ml). The samples were centrifuged at 3000 g for 10 minutes and the supernatants were transferred to vials for injection. The first-order degradation of the prodrug was monitored by LC / MS / MS as described below. The conversion to sulopenem was expressed as a percentage of the molar equivalent (50 μ?) In an enriched sample. Compounds that achieved a conversion efficiency of approximately 75% or higher were selected for a more detailed evaluation.

Stability In these experiments, the contents of a ku-zyme® HP capsule (pancrelipase preparation according to USP formed by: lipase 8000 USP units, protease 30,000 USP units and amylase 30,000 USP units; Schwarz Pharma Inc., Milwaukee, Wl, U.S.A.) in 50 ml of 100 mM potassium phosphate at pH 7.4 and mixed uniformly. Each incubation (1 ml) was performed at 37 ° C and started by adding substrate (50 μm final). Aliquots (100 μ?) Were taken at 0, 0.5, 1, 2, 3, 5, 10, and 20 minutes after the addition of the substrate and were inactivated with 200 μ? of acetonitrile / 100 mM ammonium acetate 80/20 at pH 4.5 containing an internal standard (ampicillin, 5 pg / ml). The samples were centrifuged at 3000 g for 10 minutes and the supernatants were transferred to vials for injection. The first-order degradation of the prodrug was monitored by CUEM / MS as described below. Compounds that achieved a stability half-life of approximately 10 minutes or more were selected for a more detailed evaluation.

In table 4, the unique values represent an average of two determinations in duplicate. When additional determinations were made for a given compound, the data are expressed in terms of mean and standard deviation. All compounds were analyzed using a first batch (Lot 1) of ku-zyme. Compounds 1, A, B1, and B2 were also evaluated using a second batch of ku-zyme (Lot 2), for which the data are shown in parentheses. In the human intestinal juice experiments (HIJ), the human intestinal juices of 4 individual persons (1 ml each) were pooled with 1 ml of 600 mM potassium phosphate buffer at pH 7.4. Aliquots of 300 μ? x 6 of the buffered human intestinal juice were incubated at 37 ° C after substrate supplementation at concentrations of 300, 100, 30, 10, 3 and 1 μ ?. Two prodrug compounds would be analyzed at the same time. Samples of 35 μ? at 0, 0.5, 1, 2, 10, and 20 minutes and inactivated with 70 μ? of acetonitrile / 100 mM ammonium acetate at pH 4.5 80/20 containing an internal standard (ampicillin, 5 pg / ml). The samples were centrifuged at 3000 g for 10 minutes and the supernatants were transferred to vials for injection. The first-order degradation of the prodrug was monitored by LC / MS / MS as described below. The percentage of prodrug that remained as a function of time at each concentration was adjusted in a first-order decomposition function to determine the constant of the rate of decrease of the substrate or Kdep. A linear logarithmic graph kdep depending on the concentration could be introduced in the following equation in which: [5] e p £; p [Sl = 0 * The value of Kdep with an infinitesimally low substrate concentration (in which kdep ~ KdeP [S] = o) represents the maximum consuon or intrinsic clearance rate of the system and Km is the concentration at which half of the maximum speed (Vmax) of the system. In terms of Michaelis-Menton, the intrinsic clearance CLint represents the ratio of Vmax / Km when [S] is well below Km. The substrate units for these Km studies are expressed in μ? and the intrinsic clearance (Clint) in ml / minute. Generally, compounds with an intrinsic clearance of < 0.1 ml / minute or one Km that is three times less than its solubility in water (to saturate the enzymatic activity) were selected for a more detailed evaluation.

Solubility The equilibrium solubility was determined in 25 mM phosphate buffer (pH 5) at room temperature. Vials containing an excess of prodrug in phosphate buffer were rotated for up to 48 hours. After the equilibration period, the samples were pooled, filtered with a syringe filter of 0.45 μ? T? Gelman Acrodisc Nylon and were analyzed to determine the concentration of the drug using HPLC. The HPLC conditions were: Column: C18, SymmetryShield RP, Waters, 4.6 x 150 mm, 3.5 micrometers; Mobile phase A: Acetonitrile; Mobile phase B: 0.1% TFA in water; Flow: 1 ml / minute; Analysis time: 30 minutes; Vol. Injected: 20 μ ?; Detection: 210 nm; Dissolution solvent: acetonitrile / water (50:50 v: v). The results are shown in table 4.

Gradient used: Time% A% B 0 min 5 95 25 min 95 5 27 min 5 95 30 min 5 95 Melting point The melting points were determined in an apparatus to determine the melting point in capillary MEL-TEMP 3.0 and are uncorrected.

Quantification of the Prodrug The inactivated samples from these in vitro experiments were quantified using LC / MS / MS. The separation was achieved in a column Phenomonex Primesphere C18-HC (5 μ? T ?, 30 x 2.0 mm) using a gradient binary of Solvent A (95% water / 5% acetonitrile / acetic acid al 0. 1%) and Solvent B (5% water / 95% acetonitrile / 0.1% acetic acid).

The injection volume was 20 μ ?. The column was balanced and the gradient was initiated with 100% A at a flow rate of 1000 μ? / minute. The gradient increased to 100% B in 0.4 minutes and then returned to A to 100% in 0.9 minutes. Ampicillin was used as internal standard (5 pg / ml). The effluent was analyzed by means of a detector spectrometer (Sciex API 3000) equipped with a turbo ion electrospray interface and operating in positive ion mode with a ungrouping potential of 10V, a temperature of 400 ° C and a collision energy of 25V. All prodrugs, sulopenem and ampicillin were controlled by the MRM transitions of the protonated progenitor mass to a major fragment ion in the dissociation spectra induced by the collision. The typical dynamic range of the assay varied in the range of 10.0 to 10,000 ng / ml.

TABLE 4 Reduced Carnitine Small alkyl acids such as pivalic acid that are completely substituted at the carboxylate carbon a are not catabolized sufficiently through the β-oxidation. As a result, carnitine is acylated and acylcarnitine accumulates in the tissues and in the bloodstream, decreasing carnitine-free concentrations. Thus, acids that are completely substituted in carbon a provide the potential to decrease carnitine stores in the body. See Brass, previous reference. This has been demonstrated in short-term treatments with prodrugs containing pivalic acid in which the decrease in carnitine caused a deficient oxidation of the fatty acids and an altered ketogenesis. See Abrahamsson and cois. Biochem. Med. Metab. Biol., 52, 18-21 (1994). A side chain of the prodrug that would be eliminated quickly and safely and would not decrease carnitine stores in the organism would be desirable. The metabolic conversion of certain small alkyl acids in their conjugates glucuronides provides an effective route of elimination from the organism. For example, it has been shown that valproic acid is extensively removed by glucuronidation (see Zaceara et al., Clin. Pharmacol., 15 367-389 (1988)), while pivalic acid is almost completely excreted in the form of its acylcarnitine conjugate. in humans. See Totsuka and cois. Antimicrob. Agents and Chemother., 36, 757-761 (1992). It can be seen that subtle changes in the structure can be translated into substantial differences in the metabolic disposition of these alkyl acids. The metabolic conversion of certain small alkyl acids into their glucuronide conjugates provides an effective route of elimination from the organism. It has been shown, for example, that valproic acid is extensively removed by glucuronidation (see Zaceara et al., Clin. Pharmacol., 15 367-389 (1988)), while pivalic acid is excreted almost completely in the form of its conjugate. Acylcarnitine in humans. It was interesting to compare Compound 1 and Compound B1 in terms of the tendency, or its absence, of the side chains of the prodrugs to decrease plasma carnitine after the metabolism of the intact prodrug. This was evaluated in vivo using an acute model of carnitine decrease in Sprague-Dawley rats. To understand the potential impact in vivo, the radiolabeled pivalic acid (side chain of Compound B1) and 2-ethylbutyric acid (side chain of Compound 1) were orally administered at a dose of 200 mg / kg twice daily for 4 hours. days to two groups of different animals. The pivalic acid was labeled with 14C on the carbonyl carbon (position 1) and had a specific activity of 0.482 pCi / mg. The 2-ethylbutyric acid was labeled with 1 C on the carbon adjacent to the carbonyl carbon (position 2) and had a specific activity of 0.503 pCi / mg. The doses were administered in 100 mM sodium phosphate pH 6.6 at a dose volume of 10 ml / kg. Blood samples were obtained at 24-hour intervals after the start of the study, were processed to obtain the plasma and tested for carnitine levels by LC / MS / MS. A vehicle control was completed which consisted of the oral administration of an equal volume of buffer without compound as a comparison of the basal levels. As shown in Figure 1, animals that received 200 mg / kg twice daily of pivalic acid showed higher levels of carnitine in plasma compared to the vehicle control. In contrast, animals that received the same dose of 2-ethylbutyric acid over the course of 4 days showed statistically insignificant changes in plasma carnitine, suggesting that this compound does not cause a decrease in carnitine. A different study was completed with a single dose of 200 mg / kg of each radiolabeled compound (pivalic acid and 2-ethylbutyric acid) in rats to determine the systemic dose exposure after oral administration. The oral route of administration was chosen because it is expected that most of the hydrolysis of the prodrugs will occur in the intestine before entering the systemic circulation. Samples were obtained of plasma before administration and at 0.25, 0.5, 1, 4, 8, and 24 hours after administration. Samples were quantified to determine radioactivity by liquid scintillometry and the counts were converted to ig equivalents / ml. As shown in Table 5 and Figure 2, once absorbed, the radioactivity associated with 2-ethylbutyric acid is cleared 4.5 times faster than that of pivalic acid, reflecting efficient metabolic processing and excretion of the compound . Accordingly, oral administration of the prodrug Compound 1 is not expected to cause a decrease in carnitine, whereas if it is in the administration of Compound B1.

TABLE 5 Pharmacokinetics of total radioactivity in Sprague-Dawley rats following oral administration of 14C-pivalic acid or 14C-2-ethylbutyric acid at a dose of 200 mg / kg (100 uCi / kg) Other properties For a convenient formulation and suitability as a pharmaceutical product, in some embodiments, the compound is preferably solid at room temperature, preferably easily forms a solid crystalline and is reasonably stable to degradation.

Discussion It was determined that Compound 1 showed a favorable combination of properties. In addition to being crystalline and suitably soluble in water, Compound 1 was completely converted to sulopenem in experiments with liver S9, showed a relatively long half-life in the presence of PPE and an intrinsic clearance and saturation of intestinal enzymes of human intestinal juice low. Based on these data, it was predicted that Compound 1 would show favorable clinical pharmacokinetics, which was confirmed by the clinical data described above. In addition, as indicated by its structure and the carnitine tests described herein, Compound 1 does not decrease carnitine. Thus, Compound 1 combines at least all of the following properties: good oral bioavailability, no decrease in carnitine and favorable physical properties. On the contrary, it was not predicted that other prodrugs, in particular others that carry alkyl side chains, would obtain these attributes. For example, several of the Compounds from C to AA have a tertiary carbon in position a to the carbonyl group of the ester of the prodrug moiety (e.g., Compound C). It is predicted that these present a potential decrease of carnitine. Other of the test compounds showed stability in the presence of PPE and / or conversion by S9, relatively low, which predict a stability in the tube gastrointestinal and oral bioavailability. In addition, others were not analyzed due to difficulties in obtaining samples that could be easily analyzed. See Table 4. It was also shown that the Prodrug Compound 2 exhibited favorable attributes, including its predicted stability in the gastrointestinal tract and bioavailability and physical properties. See table 4. EXAMPLES OF COMPOUNDS The present invention will be further illustrated by the following non-limiting examples. The crystalline sulopenem, which was used in the present exemplification, was prepared according to Example 11 of US 50 3729.

EXAMPLE 1 (5R.6S) -6-r (1 RM -hydroxietin-7-oxo-3-rrf 1 R.3S) -tetrahydro-1 -oxido-3-thienylthio-thia-1-azabicyclo3.2.0] hept- 2-en-2-carboxylate (2-ethyl-1-oxobutoxymethyl) Compound 1).

The title compound was prepared according to the following scheme and description.

I. ZnCIj. lCHj SOClj, CH2CI2 II. Distillation I. Nal, Acetone Step 1: 2-Ethylbutyric acid (1500 g) was added to a solution of thionyl chloride (1800 g) in dichloromethane (0.75 I) for 1 hour. The mixture was heated to reflux and controlled by GC (gas chromatography). After about 2 hours, the reaction mixture was concentrated by distillation at atmospheric pressure. After cooling to 22 ° C, dichloromethane (0.75 I) was added and the mixture was concentrated again at atmospheric pressure. Due to the extreme corrosive capacity of the reagents that were used, all the exhaust gases were passed through a wet caustic scrubber flask.

Step 2: Meanwhile, a mixture of zinc chloride (18 g) and paraformaldehyde (480 g) was prepared. The pure acid chloride, crude medium was added to this mixture for 1 hour at room temperature by mechanical stirring. After a short induction period, a significant exothermic process was observed. The temperature of the reaction mixture increased from room temperature (25 ° C) to 50 ° C in 5 minutes. The rate of addition was slowed down to control the exothermic reaction and maintain the reaction at 50 ° C. When the addition was complete, the reaction mixture was allowed to cool and was stirred at room temperature for a further 18 hours. Then n-heptane (4 L) and 10% aqueous sodium bicarbonate solution (9 L) were charged and the phases were separated. The aqueous phase was extracted with n-heptane (3.4 I). The combined organic phases were filtered and distilled in vacuo to give the crude product. The product was purified by vacuum distillation (10-20 mm Hg) yielding 587 g of chloromethyl 2-ethylbutyric acid ester.

Step 3: Chloromethyl ester of 2-ethylbutyric acid (700 g) was dissolved in acetone (3 I). To this solution was added sodium iodide (1.0 kg). The resulting reaction mixture was heated to reflux until the reaction was complete (2 hours), controlled by GC). The solution was then cooled to room temperature, where tert-butyl methyl ether (7 I) and 5% aqueous sodium thiosulfate (4 I) were added. The phases were separated and the organic phase was washed with aqueous sodium thiosulfate (4 l), pyrogen-free water (4 l) and 10% sodium chloride solution (4 l). The organic phase was dried over magnesium sulfate (350 g), filtered and the filter cake was washed with tert-butyl methyl ether (2 x 0.7 I). The filtrate was evaporated at reduced volume (approximately 2 L) to yield the 2-ethylbutyric acid iodomethyl ester, in the form of a solution in tert-butyl methyl ether.

Step 4: The crude medium solution in tert-butyl methyl ether of the 2-ethylbutyric acid iodomethyl ester of Step 3 was added to a suspension of sulopenem (750 g) in acetone (5.9 I). ??, - -dipsopropylethylamine (DIEA) (319 g) in acetone (0.5 L) was added and the mixture was stirred at room temperature until the reaction was complete. Pyrogen-free water (6.5 I) and heptane (3.75 I) were added and the phases were separated. The aqueous phase was extracted first with heptane (5 I) and then with ethyl acetate (2 x 6 I). The ethyl acetate extracts were combined and washed with 5% aqueous sodium thiosulfate. (6 I), pyrogen-free water (6 I) and 10% aqueous sodium chloride (6 I). The organic extracts were treated with activated carbon (75 g) and magnesium sulfate (150 g), then filtered. The filter cake was washed with ethyl acetate (2 x 1 L) and the filtrate was evaporated to dryness to give the crude product (0.8 kg). Ethyl acetate (2.4 L) was added and the solution was heated (45 ° C) to achieve dissolution. This solution was then filtered hot and then tert-butyl methyl ether (4.7 I) was added. The resulting suspension was granulated for 10 minutes at 40 ° C to 50 ° C and then cooled slowly to less than 10 ° C. The resulting solid was collected, washed with a 1: 2 mixture of ethyl acetate and tert-butyl methyl ether (4 x 0.5 I) and dried at constant weight under vacuum to 50 ° C to give 0.57 kg of the desired product ( 60%).

Step 5: The crude medium product (0.55 kg) was suspended in ethyl acetate (1.65 I) at room temperature. Then temperature was adjusted to approximately 50 ° C to achieve dissolution. This solution was filtered under vacuum to remove the insoluble impurities and then tert-butyl methyl ether (3.6 I) was added. The resulting solution was cooled slowly to less than 5 ° C to initiate crystallization. The solid product was collected, washed with a mixture of ethyl acetate and tert-butylmethylether 1: 2 (4 x 150 ml) and dried at constant weight under vacuum up to 50 ° C, yielding 0.48 kg of the desired product (yield 86%). It was determined that the crystalline material was not solvated.

H NMR (DMSO-d6, 400 MHz): 5.71 (m, 3 H), 5.19 (d, 1 H, J = 4.56 Hz), 3.92 (m, 2 H), 3.81 (m, 1 H), 3.70 (m, 1 H), 2.96 (m, 1 H), 2.80 (m, 1 H), 2.65 (m, 2 H), 2.36 (m, 4 H), 2.19 (m, 1 H), 1.45 (m, 4 H), 1.10 (d, 3H, J = 6.22 Hz), 0.78 (t, 6H). PF: 105 ° C; Mass. Esp .: (M + H) + 478. MW: 477.92 g / mol; Form Molec: C19H27NO7S3. Solubility in water (phosphate buffer at pH 5, 25 ° C): 1209 pg / ml. The crystals of Compound 1 prepared in the manner of Step 5 above were subjected to fine crystal diffraction by X-rays. The samples were analyzed on a Siemens D500 automated fine-crystal diffractometer fitted with a graphite monochromator and an X-ray source. of Cu (? = 1.54 Á) which was operated at 50 kV, 40 mA. A 2T calibration was performed using a NBS mica standard. Sample preparation was performed using a zero background noise sample plate. The diffraction pattern of these crystals of Compound 1 is shown in Figure 3 and tabulated in Figure 5.

EXAMPLE 2 (5R, 6S) -6-r (1 RH -hydroxyethyl-7-oxo-3-yr (1 R, 3S) -tetrahydro-1 -oxido-3-thienynthio1-4-thia-1-azabicyclo3 .2.01hept-2-en-2-carboxylate (2-ethoxy-2-methyl-1-oxo-propoxy) methyl (Compound 2).

The title compound was prepared according to the following scheme and description. Stage 1 Stage 2 O DIPEA r | NaH, Elt H3C CH3 ^ (91%) HaC CH3 DMF. O'C (47%) In steps 1-4, 2-hydroxy-isobutyl acid was protected with benzylic bromide, alkylated with ethyl iodide, deprotected and esterified to give 2-ethoxy-isobutyric acid chloromethyl ester. In step 5, in a suitable reaction flask, it was dissolved sodium iodide (23.9 g, 159.45 mmol, 1.6 eq.) in acetone (96 ml). Then 2-ethoxy-isobutyric acid chloromethyl ester (18 g, 99.65 mmol, 1 eq.) Was added in the form of a solution in more acetone (18 ml), and the resulting reaction mixture was heated under reflux under a nitrogen atmosphere. for about 2 hours. The reaction was controlled by GC. When the conversion was complete, the reaction was allowed to cool to room temperature with stirring. The reaction was then partitioned between heptanes (120 ml) and 10% aqueous sodium thiosulfate solution (105 ml). The contents of the reaction vessel were stirred for at least 5 minutes, and then the phases were allowed to separate. The light organic phase was reserved, and the heavy aqueous phase was discarded. The organic compounds were then washed with a second portion of 10% aqueous sodium thiosulfate solution (105 ml), and after the separation the heavy phase was discarded again. The organic phase was then washed with 10% aqueous sodium chloride solution (105 ml). The heavy aqueous phase was discarded and the organics were concentrated under reduced pressure (< 35 ° C). This yielded 16.26 g of 2-ethoxy-isobutyric acid iodomethyl ester which was used in the subsequent chemical reactions without further purification (assay: ~60%). In Step 6, sulopenem (13.92 g, 39.83 mmol, 1 eq.) And acetone (110 ml) were added to a suitable reaction vessel under a nitrogen atmosphere. Then 2-ethoxy-isobutyric acid iodomethyl ester (16.26 g, 59.9 mmol, 1.5 eq. At a power of 100%) in acetone (14 mL) was added and the suspension was stirred for a minimum of 10 minutes.

Then?,? - diisopropylethylamine (5.1 g, 39.54 mmol, 1 eq.) In acetone (14 ml) was added, maintaining an internal temperature of < 35 ° C (exothermic reaction). The reaction mixture was stirred at room temperature overnight (after about 2 hours, the sulopenem dissolved). The reaction mixture was then partitioned between heptanes (80 ml) and water (129 ml), and the contents of the reaction vessel were stirred for at least 5 minutes. The phases were separated and the light organic phase was discarded. The heavy phase was washed with more heptanes (80 ml). Again the phases were separated and the light organic phase was discarded. The content of the reaction vessel was then concentrated approximately 50% at reduced pressure, maintaining an internal temperature below 35 ° C. Ethyl acetate (120 ml) was added and the contents of the reaction vessel were stirred for at least 5 minutes. The phases were allowed to separate and the light organic phase was reserved. The heavy aqueous phase was back extracted with more ethyl acetate (2x120 ml). The combined organics were washed with 10% aqueous sodium thiosulfate (120 ml), water (120 ml) and 10% aqueous sodium chloride (120 ml). The organic compounds were then treated with activated carbon (2.9 g), celite (2.9 g) and magnesium sulfate (MgSO4) (8.2 g) at room temperature and stirred for at least 1 hour. After removing these solids by filtration, the solution was concentrated under reduced pressure, while maintaining an internal temperature lower than 45 ° C (ethyl acetate, e.g. 76.5-77.5 ° C).

Step 7: The resulting crude Compound 2 (23 g) in ethyl acetate (100 ml) was heated almost to reflux to completely dissolve the solids, and then tert-butyl methyl ether (100 ml) was added gradually, maintaining an internal temperature of between 60 ° C and reflux. The resulting mixture was stirred slowly between 60 ° C and reflux for 5 minutes, and then granulated for a minimum of 1 hour at 5-15 ° C. The off-white product was filtered, washed with methyl tert-butyl ether (MTBE) (28 ml) and dried under vacuum at room temperature for at least 16 hours. This provided the product (Compound 2) in the form of a white solid, (12.57 g, 63.9% yield). The crystals of this product were subjected to diffraction of fine crystals by X-rays. The samples were analyzed in a Siemens D500 automated thin-glass diffractometer fitted with a graphite monochromator and a Cu X-ray source (? = 1.54 Á) which operated at 50 kV, 40 mA. A 2T calibration was performed using a NBS mica standard. Sample preparation was performed using a zero background noise sample plate. The diffraction pattern is shown in Figure 4 and is tabulated in Figure 6. NMR of d1? (DMSO-d6, 400 MHz): 5.83 (d, 1 H, J = 5.81 Hz) 5.73 (m, 2H), 5.20 (m, 1 H), 3.92 (m, 2H), 3.81 (m, 1 H), 3.70 (m, 1 H), 3.28 (c, 2H, J = 7.05 Hz), 2.96 (m, 1 H), 2.80 (m, 1 H), 2.65 (m, 2H), 2.36 (m, 1 H), 1.29 (s, 6H), 1.10 (d, 3H, J = 6.63 Hz), 1.00 (t, 3H, J = 6.63 Hz).

MP: 111-113 ° C; MW: 493.62 g / mol; Form Molec: C19H27NO8S3. Solubility in water (phosphate buffer at pH 5, 25 ° C): 2900 pg / ml.

Claims (1)

1. NOVELTY OF THE INVENTION CLAIMS 1. - A compound of the formula: 2. The compound according to claim 1, further characterized in that it is (5R, 6S) -6 - [(1 R) -1-hydroxyethyl] -7-oxo-3 - [[(1R, 3S) -tetrahydro-1 -oxido-3-thienyl] thio] -4-thia-1-azabicyclo [3.2.0] carboxylate (2-ethyl-1-oxobutoxy) methyl. 3. The compound according to claim 1, further characterized in that it is (5R, 6S) -6 - [(1 R) -1-hydroxyethyl] -7-oxo-3 - [[(1 R, 3S) - tetrahydro-1-oxido-3-t-carboxylate (2-ethyl-1-oxobutoxy) methyl in the crystalline form having a fine crystal diffraction pattern by X-rays containing peaks at diffraction angles of 4,835, 9,624 , 12.768, 14.483, 16.712, 17.080, 18.230, 18.649, 19.322, 20.527, 21.137, 22.240, 22.511, 23.658, 25.732, 27.340, 27.844, 29.385, 29.651, 30.498, 30.917, 32.375, 33.814, 34.746, 35.312, 35.736 and 39.463 (2-Theta °). 4. - A compound of the Formula: 5. - The compound according to claim 4, further characterized in that it is (5R, 6S) -6 - [(1 R) -1-hydroxyethyl] -7-oxo-3 - [[(1 R, 3S) -tetrahydro- 1-Oxido-3-thienyl] thio] -4-thia-1-azabicyclo [3.2.0] hept-2-en-2-carboxylate (2-ethoxy-2-methyl-1-oxopropoxy) methyl. 6. The compound according to claim 4, further characterized in that it is (5R, 6S) -6 - [(1 R) -1-hydroxyethyl] -7-oxo-3 - [[(1 R, 3S) - tetrahydro-1-oxido-3-thienyl] thio] -4-thia-1-azabicyclo [3.2.0] hept-2-en-2-carboxylate (2-ethoxy-2-methyl-1-oxo-propoxy) methyl in the form crystalline having a fine crystal diffraction pattern by X-rays containing peaks at diffraction angles of 4,953, 9,534, 9,978, 12,916, 15,041, 16,278, 17,110,118,182, 18,810, 21,700, 22,153, 23,603, 25,025, 26,542, 27,830, 28,894, 30,359, 31,528, 36,426, 38,031 and 39,465 (2-Theta °). 7 - A pharmaceutical composition comprising the compound of any one of claims 1 to 6 formulated to be orally administrable with or without one or more excipients and / or another or other active ingredients. 8. The pharmaceutical composition comprising the compound according to any one of claims 1 to 6 and probenecíd formulated to be orally administrable with or without one or more excipients and / or another or other active ingredients. 9. - A pharmaceutical composition comprising from about 800 mg to about 2.5 g of a compound of any one of claims 2, 3, 5 or 6, formulated to be orally administrable with or without one or more excipients and / or other other active ingredients. 10. The use of the compound of any one of claims 1 to 6 and probenecid in the manufacture of a medicament useful for treating a bacterial infection in a human, wherein said medicament is adapted to be orally administrable. 11. The use of a compound of any one of claims 1 to 6 in the manufacture of a medicament useful for treating a bacterial infection in a human being, wherein said medicament is adapted to be orally administrable. 12. The use of the compound of any one of claims 2, 3, 5 or 6, in the manufacture of a medicament useful for treating a bacterial infection, in a human, wherein said medicament is adapted to be orally administrable. 13. The use as claimed in claim 12, wherein the medicament is adapted to be orally administrable in an amount of about 500 to about 2500 mg twice a day or three times a day. 14. - The use as claimed in claim 12, wherein the medicament is adapted to be orally administrable in a dose of about 800 to about 1000 mg twice a day. 15. The use as claimed in claim 12, wherein the medicament is adapted to be orally administrable in a dose of approximately 2000 mg twice a day. 16. The use as claimed in claim 12, wherein the medicament is adapted to be orally administrable in a dose of approximately 2000 mg three times a day. 17. - The use as claimed in claim 12, wherein the medicament is adapted to be orally administrable in a dose of about 7 to about 25 mg / kg twice a day. 18. - The use as claimed in claim 12, wherein the medicament is adapted to be orally administrable in a dose of about 17 to about 45 mg / kg twice a day. 19. The use as claimed in claim 12, wherein the medicament is adapted to be orally administrable in a dose of about 17 to about 45 mg / kg three times a day.